Study on high purity single-photon emission from InGaN quantum dot embedded in a GaN nanowire using focused-ion-beam induced luminescence quenching method

Abstract

Single-photon sources are a crucial component for quantum information technology. Among various quantum dot structures, the quantum dot embedded in a nanowire structure offers reduced background noise compared to other quantum dots due to the absence of a wetting layer. Moreover, it facilitates easy integration with other optical structures by enabling the positioning of quantum dots as desired. However, directly using quantum dots with high density as single-photon emitter is challenging due to unwanted emission signals from adjacent quantum dots. This thesis demonstrates the utilization of highly dense quantum dots as single-photon emitter via a selective luminescence quenching method using focused-ion-beam. We obtained a single quantum dot emission from quantum dot embedded in a nanowires with high density (~$1.5 \times 1010/cm^2$) by using Ga focused-ion-beam technique. Also, using the site-selective luminescence quenching method, we obtained a single-photon emitter based on InGaN quantum dot with a high single-photon purity more than 94%.